Finally got it working. On the Primary: I flushed, uninstalled, rebooted multiple times. On the Secondary: I flushed, uninstalled, rebooted multiple times. I then installed this new version on Primary and installed an older version of Multiplicity on the Secondary. Thanks Stardock for getting us this new version. Once an official update is released, then I will update the Secondary.
Downloaded new .exe. Rebooted both computers. Zero joy. The exact same issue remains. I'll keep testing and rebooting to give it a thorough look and report back if things change.
I've always said that Neil Banfield should be on the Mount Rushmore of great people!!!
There is another KVM called Barrier. It is quite terrible when compared to the Stardock software. However, they have a setting called "Elevate" that when clicked solved my problem. Without that setting being clicked, their software behaved exactly like the problem described in this thread. Other problems keep me from switching to their product. I really like Multiplicity and hope a fix is eventually found.
Mouse Without Borders has the same issue as Multiplicity.
Same problem as everyone else where secondary machine mouse is moving primary character. Still not working after doing a complete uninstall / purge and reinstall on both machines using instructions from: https://forums.stardock.com/486104/multiplicity-support-faq#reinstalling No success trying the x-mouse trick found elsewhere. However, clicking off primary EQ program onto taskb